Hey E4!
I sold a fair amount of graded stuff in 2024 (just before the boom RIP) to fund other hobbies; it was the right move for me at the time.
I’m pretty content with the smaller graded collection, although there’s one card I miss having in the collection.
I was wondering if you have sold off a card, only to want to buy it back again at a later date?
Trouble is the card is now worth 3x what I bought it / sold it for haha, price memory is painful!
dont remind me.
I haven’t done this with cards but definitely have done this with books. 
I donated a lot of my books when moving across the country the first time for school… Only to realize I still loved a series, so I bought them all again when they came out with new covers (the Warriors series lol).
And of course I did this again two years ago when my mom asked me to clear my books from her attic. I went through 14 boxes of books, and somehow, very painfully, kept basically only one. Then realized a little while later I had donated my old Holly Black books when I probably should have kept them. 
(I did keep the signed books I have from her, but not the Tithe series - the new covers are fine but I miss the original ones I had lol).
Yeah, I did this a lot in the first 10 years of my collection. I think it’s super normal when you are in a fixed resource environment and still exploring your hobby interests.
I’d encourage you to totally ignore it. You’re not buying with old dollars, enjoying it in prior years, or making trade-offs with old opportunities. You’re here now, buying now, for today’s collection.
And if it’s a fundamentally good card that you believe in long term, you’ve got your own little reminder to look elsewhere when the shiny thing comes around next time.
All the time
I sold all my Battle Festa cards in 2019 but instantly regretted it. I then quickly went online and bought back every copy from Japan and have happily kept them in my collection ever since..
Most recently I bought the Stampbox Cramorant in a PSA 10. My friend was in Japan in February and found a copy at one of the shops he visited and gave me the heads up. Scored a great deal for me 
I have but so far I’ve been lucky enough to reacquire the cards I sold at a lower cost. If you are are bullish on Pokemon cards in the long term I wouldn’t let price memory deter you though. Sometimes you just have to move with the market
1st Edition Team Rocket Charizard Holo PSA 10 and bought back a PSA 9 recently.
Sold my ex emerald regular holo kyogre in 2021 that I graded myself and bought it back 9 months ago, the same copy/cert, for cheaper than what I sold it for. Thank you CGC and randomly good timing
The Eeveelution Premium collection vmax/v sets from those cool box sets. Had 2 full psa 10 sets i dumped few years ago. Just recently been buying them back. shouldve never sold such cool, exclusive promos.
Absolutely I have. I think it’s necessary as collection interests shift or as life priorities change. Buying the cards back feels like being reunited with old friends. I’m hoping to do it again soon after this boom calms down.
I have bought and sold 6 copies of a shadowless charizard
All were upgrades except the psa 9 was sold to achieve major life milestones
PSA 10 incoming
I wish 
Updated it. Got one back in the collection and will see if I’m able to rebuild the shadowless holo set. TBD if I can do it but happy to be back in the hobby. Although I still dabble in football cards
Yuuuuup. Both higher grade, lower grade and raw. Depends on the card and my motivation. It’s nutty and fun as hell to sell the 10 (usually vintage) and buy a much cheaper 9, then the 9 rises to the level of the previous 10 so sell that and buy an 8, then sell the 8 for the price of the old 9/10 and buy the much cheaper 7, etc. If I live long enough my PC will be down to mostly 3s and 2s while I supplement my income for years while still enjoying my collection. I buy 10s a lot but for the same artwork I’ll trade out for lesser grades every day of the week.
Never tbh, mostly because I almost never sell. And if I sell, 90% of the time they’re just duplicates anyway. 
The only thing that does come to mind though: when I was a 7 y.o. kid, I traded away the Chansey from my first Base Set pack for a Pidgey, Pidgeotto, and Vulpix (since I only cared about more cards, and not about holos), and a few years later I traded away my Legendary Collection Reverse Foil Moltres I pulled (for an Ancient Mew).
Both of those cards I bought about 2-3 years after I started collecting again (when I was ~25 years old), for nostalgia sake. Luckily, 2017-2018 was still a cheap time to buy those kind of cards. 
Greetz,
Quuador
Yes only once, one of my extra copies of Stadium Challenge Deoxys. Sold it after the tournament in 2005 bought it back around 2018 because my friend was going to sell his collection. I claimed that card, wanted it back.
Several years ago I bought mint raw copies of Japanese Rayquaza & Giratina Lottery Promos (thanks West for the link) for my BW binder. They weren’t sealed but were insanely clean, so I ended up grading and eventually selling them.
I bought raw copies back for my binder soon after. Had honestly wanted to get PSA 10s again cause I thought they were undervalued (was in a financial crunch when I first sold) but now they have climbed so much that won’t be possible. Grateful to at least have played binder copies!
