Buy trumpet/trombone advice? 2nd hand instruments?

Oldest child (~10) has told me recently he’s interested in learning trombone, or maybe trumpet. In the US I’d probably ebay a 2nd hand Yamaha, Bach, Selmer, etc. In Taiwan, I don’t know what to do. I see that online (yahoo/ruten) they have 2nd hand Jupiters, Yamaha, etc., but the prices seem high to me. My big dilemma is buy here or wait until I get home in another 6-8 months. Is there a place where people sell 2nd hand instruments in Taipei? It looks like a number of brands (Jupiter, Carol) are actually made in Taiwan–I wonder how hard it would be to get something decent here in the 8-12,000 range. If I wanted to look at cheap end new instruments, do you think music stores would let me try out several of the same model to compare playabability or is this like everything else and the instruments stay in plastic wrap until you bring them home. I played trumpet in high school, so not totally new to this. Any thoughts? I live in Taipei.