Even if you could do what you say I don't see how it would beneficial. You typically cannot come in on the Button (blinds would not move). You can wait for the BB to come to you or you can pay a bb to enter from any position but the Button or SB.
Assume you can enter from the Cut Off (just before the Button) for the bb and it is 6 handed. You could play 3 hands for the price of a bb by sitting out the blinds.
If you stay in the game you play 6 hands for the price of sb + bb. The extra 3 hands (Button, SB, and BB) cost 1/2 as much. I will take the Button, SB, and BB for the price of a sb every time. The Button is the best position and SB and BB can catch good cards.
If you must pay sb + bb to enter on the CO you are paying the same price to play 3 hands versus 6. Not a good strategy.
Plus if you sit out 1/2 the hands it is boring and your hourly rate is cut in 1/2.
I use lower case for the cost sb, bb and upper case for the position SB, BB.