Actually, a T500-T1000-T5000-T25000 set works very well for tournament stack sizes of T100K (100bb) to T300K (300bb).
Best scenario is either 100 chips of each denomination (10 players) or 200 chips of each denomination (20 players). T100K stacks are 10/10/7/2; add more T25K chips for larger stacks. A 400-chip (or 800-chip) set includes the perfect amount of color-up and re-buy chips (or add-on chips for larger stacks). In fact, every 2-table tournament chip set that I own (with large denominations) has at least 200 chips of each of those four denominations for exactly those reasons. It is most efficient when using T250K starting stacks with no re-buys: every single chip gets used.
As far as the OP's proposed tourney set is concerned, there are four glaring problems:
- 6 x T500 chips per player is not enough
- 27 x T1000 chips per player is way too many
- using T10,000 chips in play with T5000 and T25K chips is needless, inefficient, and confusing
- the set does not contain enough T25,000 chips
Needless to say, I don't like that 1000-chip set breakdown at all. There are nearly three times as many of the T1000 chips you need (they total over half the set), and the 50 x T10K chips are pretty much a waste of money, too. That's 400 total chips you don't need, out of the 1000 you are purchasing. I highly recommend against it.
I am also not fond of the inconsistencies present in the posted blind structure. The blind increases range from 25% to 100% (averaging 47%), and the T500 chips are used for only three levels. Expected maximum length of the event for 20 players is 5:40 plus breaks (about 5 hours plus breaks for 12 players).
Below is a much more consistent T100K blind structure for that number of players and total time frame - the blind increases range from 25% to 50%, averaging just 40%:
lvl sb bb
L1 500 1000
L2 500 1500
L3 1000 2000
L4 1500 3000
remove T500 chips
L5 2000 4000
L6 3000 6000
L7 4000 8000
L8 6000 12000
L9 8000 16000
remove T1000 chips
L10 10000 20000
L11 15000 30000
L12 20000 40000
L13 25000 50000
L14 35000 70000
remove T5000 chips
L15 50000 100000
L16 75000 150000
L17 100000 200000 ***
L18 150000 300000
L19 200000 400000
Expected maximum tournament length for 20 players with 20-minute blind levels is 5:40 (plus breaks), or about 5 hours (plus breaks) for 12 players. Add or subtract 15 minutes of total tournament time for every 1 minute change in the blind level times. For example, increasing the blind times by 4 minutes (to 24 minutes) adds an hour total time to the event.