My personal opinion is that whilst I understand the reasoning behind wanting to save as much money as you can, in the end it may be a false economy.
I think you have to put it out of your mind that what you are paying for a small piece is the same as it would be for a larger piece.

You have to ask yourself if it is worth what it will cost you to solve a problem and make you feel better about yourself.

There are big advantages to having a piece that fits perfectly and that you don't have to cut up & mess around with. ie) Choice 2.

If you go for one of the alternatives, you might initially save money, but the simplest mistake in cutting could mean that you've wasted all your money and not got anything like what you wanted.

Further down the line, you could rethink it and maybe go for Choice 3 because by then you will have a better idea of what you need the piece to do for you.

Its just my opinion and best of luck.