if you want something small like 5mm you should be able to get away without hubcentric ones, but anything more than that, you don't just want cheap spacers, you want proper bolt on spacers
I'm not a fan of either bolt on or hubcentric spacers. They're a safety hazard especially bolt ons at high speeds and stopping. Hubcentric aren't that much better for relieving stress on the hubs and studs. Not to mention voiding your insurance in an accident.
These cars dont have a lot of space under the guards. So its easy to find rims with the correct width and offset to fill them. Buy the right rims in the first place.