As my stash has grown larger, I've become quite a cheapskate, too, in model buying. I almost never pay MSRP for them. I either wait until they go on sale at one of the big internet places, my LHS, or find them on ebay. Generally, $25 is my limit for 1/48 scale aircraft. If its a subject I really want in my favorite scale (1/48), though, I'll throw the limit out the window. I did pay $28 plus shipping for an S-model vacform Vultee P-66 Vanguard. Is the kit worth that, especially a vacuform? By itself, not even close. But I really wanted a 1/48 P-66, and in this scale, there's no other game in town.
I unfortunately have a real mental barrier with the prices of 1/72nd scale aircraft these days. I guess because I built so many of them as a kid, buying them for a dollar or two. I just can't get over the $10 barrier for a single engine 1/72nd scale aircraft, and I don't care how much resin/PE is thrown in. Guess this is why I could never settle for Sword's 1/72nd P-66, even though the P-66 was at the top of my want list, but would have paid even more than I did for the 1/48.