My situation is similar, I mean we have a league here but there are only little kids and I rarely go there. Still I support the shop by getting my sleeves and boxes there through I could get them on ebay for less money, but buying boosters is just ...
I'd gladly pay entry fees for tournaments because I understand that the shops have to make their money somehow and I dont want the venues where I play (there are in other towns anyway so I just go there for tournaments) to close. I also play PRs.
But as much as I want to support the shop, buying boosters is juste a waste of money, you nearly never get something thats worth the booster price (which is higher here in the US). And if you get a LvX you still have a high chance to get somethign absolutly crappy or a tin lvx.
I'd really rather support the shop by just giving them the money for free so I can show I want to help any apprectiate that the hold tournaments. But buying boosters is lying to yourself.
"I want to support the shop, so I have to buy something, although I dont want to and know it'll be a waste of money". If the shop would really need support I'd rather give them the money for free or buy tons of sleeves instead of buying boosters.