And a much less important reason for not starting at T1000 (or T5000) is that when people make bets or count their stacks they don't use the word "thousand" very often. When everyone knows the context that each chip is already in the thousands they just drop the word and say "3" or "I'll bet 50" instead. Having a T1K or a T5K base tournament is the same as a T1 or T5 base but you've just added on the word thousand for funsies (which is perfectly valid for novelty, especially when you have
@cpac54 Rio set

, but not for a standard tournament, in my opinion). When doing a T500 base set you start the tournament betting in "hundreds" (ie 15-hundred, 85-hundred etc) and then switch into betting thousands later on (5-thousand, 45-thousand etc), so in a way the denominations actually matter a little more and serve more of a purpose.