Any legalities aside (ie seats being not certified and racing harnesses not being legal in most cases on public roads without std belt as well) you shouldn't really skimp on price when it comes to safty. Some points to consider.
- Racing harnesses are costly (atleast for good ones)
- Racing harnesses have a limited life (i think 3 years) when actually used at cams/fia events, ie they have an expiry date (due to UV damage of material i believe)
- You need somewhere to attach a harness (paying special attention to angles etc) so many people i see attach them low in the rear, real no no !
- Last time i checked in autobarn a lot of the seats appeared not to have the australian standard sticker i think they require, hence for off road use only (could you get defected)
- If you have a 2 door car and rear seats fixed buckets means the rear seats should be removed an the car rego'ed as 2 seater
btw i have for sale if anybody is keen ($$$) 2 by bride carbon/kevlar racing buckets. Havn't thought of a price but there expensive, would consider swap for say 2 x new recaro SR seats (geniun). Dont quote me but i think you will fund those bride racing seats are 3000-4000 each ! (due to being carbon kevlar and not just frp material).