I go to ebay and select my era of die-cast vehicles and then sort them starting lowest price first and scroll.
I've found some really nice vehicles for $10 -$15 shipped sold by folks moving someone else's collection.
The same motorcycles MTH sells you can get directly from China without a box for a fraction of the cost.
Another instance, I got a fantastic deal on a 1939 peterbilt tractor trailer from trainz on ebay because it was incorrectly described as h.o. scale.
Lots of nice die-cast for the layout if you do some searching.
Buying die cast directly from a store or dealer often means paying much more. Just like anything else. As Big Jim says, if it's worth it to you. That's all that matters.
Having said that. If I didn't spend so much on trains I could easily find myself collecting die-cast vehicles. Especially older trucks and heavy equipment.
