The most expensive things to maintain on a detached home are usually the roof, windows, and the furnace. Before buying, make sure those three things are in good condition, that's important.
You can then begin to set aside funds for other maintenance that will come up.
A few other things I think are SUPER important to keep in mind:
1) @faithfuldividends is bang on about Youtube, DIY will save you a tonne of money over the years.
2) The smaller the home, the lower your operating/maintenance/reno costs will be. Whenever I see a giant, custom home, I think about how much the reno costs will be in 20 years when the owners want/need to update it.
3) If you stay well within budget in buying the home, then you'll have more cash flow flexibility to maintain it.
4) Avoiding the HGTV trap is key. A new $40,000 kitchen is not 'required maintenance'. Sounds silly, but many people confuse luxury reno's with the basics of home maintenance.
As for condos, I haven't a clue, never owned one! lol.