why dont you just use these tyres until they get useless and than change it.
that saves your money for now till they get old
I think you wont be able to find 155/80/R13 80 will be difficult to find in brands other than General. I could not find a set of tyres that match standard general tyres 80 sidewall height for a GLI and had to go for 70s
If u haven't yet bought the tyres, go for 165/75 R13 in Bridgestone Potenza.
for more info visit http://www.kouki.co.uk/Utilities/tyresizer.asp
Can you see the date of the post?