Although I'm straight-razor-curious, I'd second the double-edged safety razor suggestion. I'm a fairly recent convert and I don't anticipate going back - cheaper (though there are up-front costs), better results, better experience and less waste.
FYI, I picked up a variety pack of blades (100 blades among 15 or so varieties, for something like 15 bucks on Amazon) and it's a good way to try a bunch of stuff to find the razor/blade combo that's right for you. So far, I'm liking Astra SP best.
the biggest advantage with DE or SE/straight razors is that you can adjust the attack angle and therefor depth of cut.
the advantage with mach3 and mach5 and whatever is that they are fast. really fast.
if i could get maybe half a day smooth with braun and philips shavers (their best sh1t)
i could get 1-1,5 days with mach3s going against the grain.
and i get about double that with a straight. for the simple reason that you can angle it so it cuts deeper.
economy?
with shaving machines you have to buy new ones every 2-3 years or so, then the battery dies at the very least. a good one is 150-200 or so.
with DE ones and all replaceable blade ones you need to buy blades.
with mach 3s i can can get 2 good shaves and maybe 2 crappier ones after that. and i get exactly 1 head shave, and you can't do head shaves with dull ones. well you can, but you kinda dont want to.
longest lasting ones are the black mach3, just mach3, all other ones that are newer and "better" like mach3 turbo will last half as long at best. the mach5s are a ploy imo since all cutting and wear takes place on the very first blade only.
with straights and kamisoris you have the razor and then stones then a strop.
strop 60-70 maybe
stones. maybe a shapton pro 2k 50 bux, and then the naniwa SS 12k or shapton 12k. 90-100
then the razor. 100-300 or so.
Buuuut you can keep this set for your entire life. and you will not wear it out. so yes the initial outlay is higher but in the end its the cheapest.
its also fun and satisfying doing things yourself. this alone makes it worth it from the start imo. this is the most important thing of all of them.