Turnkey price renegotiated to accommodate repairs?

[RI N.]

my understanding from BP is that a TK property is rent ready with all major systems functional for several years. Thus roof w long life remaining (i.e. 10yrs min), hvac, plumbing and electric all new or much life remaining so that there will not be capex for at least 5+ years. Are my assumptions accurate?

With this understanding, my inspection revealed several deficiencies including roof replacement. Some things were trivial but the functional components of the home I wanted fixed. The TK provider now wants to change the price bc they're over their budget for repairs. I feel our contract which was for a fully performing property should not require any short term repairs and, thus, replacing the roof and fixing plumbing/electric are his responsibility and risk. I'm paying 'his' price (no negotiation allowed) so it shouldn't change bc his estimates were wrong? I want to be fair and don't want to take advantage but I don't think it's fair that I incur the expense of newly uncovered repairs.

Watdoyathink?