8x10 Ilford HP5? Or Kodak Tri-x?

I have been doing some calculating, comparing the 8x10 sizes of HP5 and Tri-x. If I buy a fairly large volume of the 2 films I can get the Tri-x for about $6.10 a sheet and the HP5 for $4.04 a sheet. That means for every 2 sheets of Tri-x I can buy 3 sheets of HP5. I love Tri-x but that's a huge price difference. Which film to use?

As I develop my skills in the field with the 8x10, would it not be smarter to have more film to play with? Maybe I can use HP5 for a few years and see how it goes, if all goes well I can keep using the HP5 but if I feel Tri-x is still the better film I can change back to it. I could switch back to the Tri-x when I am more on top of things and making fewer mistakes, better compositions, nicer portraits etc.

Something else to think about.