I have/have had all 3 in the garage coincidentally

I'd rank my preference as below, without knowing the prices that you have been offered for them

1. Mazda 3 2009 2.0
2. Proton Inspira 2011 2.0P
3. Honda City ivtec 2009 1.5E

All 3 cars maintenance is decent, no major problems with all 3. Inspira is most comfortable but service was the worst (Proton service centre). Mazda service is quite OK, Honda ok ok (my service centre usually washes the car for free)

Mazda 3 is best to drive, City is a whole different class from the other 2 (much less refinement, B-segment after all). Proton has a stigma attached to it, but if you can look beyond that, its decent

No ideas on the M3 1.6 and Inspira 1.8. Similar body shell but totally different engines.

I think similar in terms of parts availability and service centre wait time. All 3 of mine haven't had major issues that required warranty, so can't tell you much.

As for service centres, from my experience there are good and bad ones for every brand. Mazda used to be poor but have recently bucked up, but I'm not sure how it will be since their sales figures rose considerably.

Ironically, I find Honda the worst, mainly due to the fact that it is the most crowded.

Haven't paid much attention to cost, which means that they didn't cost a bomb