Best place to buy booster cases?

If I’m looking to buy booster cases (6 booster boxes) is ebay the best bet? Another question I was wondering, are distributors increasing prices or is it the TCG company? Seeing prices that used to be 500-600 now starting between 800-900. Obviously the demand is the reason but I’m wondering who is setting the price, I didn’t think distributors would be allowed to increase the price themselves.

Prices for booster boxes were always much lower than the suggested MSRP which is around $143 per box. Since demand has skyrocketed, retailers can actually list boxes for around MSRP when a set is released instead of the $90 and under per box they use to list at during release. I’m guessing The Pokemon Company and/or distributors have increased prices a bit as I don’t see why they wouldn’t. Gamenerdz is a site I’ve bought from before and they usually have cheap prices for new releases, but sell out really quick. They are sold out of preorders for chilling reign. Seems like new sets are selling for more when they are released and then coming back down when supply starts meeting demand. Battle styles use to be around $140 per box and is under $100 now on eBay.