After 3 hours of playing (distributed over 4-5 sessions), I was able to upkeep a 8K horse, 3.5K crossbow (heirloomed, but I'm not sure if it affects price), 5k longsword (heirloomed), 1k worth of armour and bolts (occasionally normal 150 gold ones, occasionally 2k gold ones) and actually earn money (maybe 8K extra).
I would not say upkeep is too stringent.