If you're looking for something collectible but somewhat more reasonably priced, take a look at TANKS! from Gale Force Nine and Battlefront (the people behind Flames of War).
You will have to build the models, and paint them if you feel so inclined. The starter set is $25USD with three tanks. Expansions are $10USD and contain a single tank model and a bunch more cards, kind of like Star Wars: X-Wing but with WW2 tanks instead. Over time, the game scales up to around 3-6 tanks per side, depending on tank size/strength.
If you're feeling thrifty, note that the scale (1/100) is produced by many other (and cheaper) manufacturers, including the more recent expansions from Axis & Allies Miniatures, and that the TANKS! starter set includes cards for all of the tanks in the initial release. So you might find that you can use your existing collection to expand the game quite a bit already!