A few words.
924’s are less reliable, parts are harder to find, and are a larger pain to work on in most cases. However, for the most part they are on par with their 944 stable mates for when it comes to costs. Unless you happen to know which parts cross (since all pre 85’s 924’s use the Audi engine IIRC). Which isnt the easiest thing to figure out. If you plan on launching the car, doing burnouts etc, plan on buying a few extra transmissions. The Transaxle should be removed every 60k miles and reshimmed and inspected ($1800), waterpump and timing belt should be done every 30k, along with seals and rollers/tensioners ($1200). Etc, etc.
Buy a 944/944 Turbo/944 S2/968 if you want a front engined Porsche, dont waste your time with the 924 unless you want something unique that has a ton of upkeep (aka you’re already a 944 owner and have a ton of spares laying around). Not to mention the 924 is narrow body and loses out on those sexy flares. Oh yeah, and the fuel and ignition system is significantly inferior on pre 86 924’s. Honda reliable? Sure, if you’ve done ALL of the required maitenance and updates. Budget atleast $1-2k per year for a 924/944 maitenance, $2k or so for a 944S2/968, and $2-5k per year for a 944 Turbo (this figures are for the first 3 years of ownership).