Suspension components I'll let the garage do as the bolts often need a fair amount of persuasion. I'll do all the routine stuff and have the electronic service manual for the car. The only issues I've had with my 2002 Nissan Primera have been air con radiator (holed by road debris), new air con pipe - fractured, and a new cat. Unfortunately each of these jobs were £400-£600, but over the 13 years I've had the car it's not bad.
I do the routine stuff myself, and have done central locking motors on the wife's yaris and even changed the built in 'radio' when it went faulty - dash out job but it's a known issue, and I found a replacement OEM unit on
ebay for £25.
Finding a good independent is sometimes tricky. Fortunately we have one very good garage that is very busy and seems to look after just about everyone's cars. I also use another specialist for air con.
Stuff needing big spanners goes to the garage.
There is a known issues with a number of Nissans - whilst the bodywork and underneath is well protected, the radiator support panel isn't - and it can rust to bits. Fortunately it's something I knew about and when it started to corrode, I hammerited the exterior and used spray grease in all the holes and coated the inside. This stopped the corrosion. I do regularly top up underseal on the suspension arms and struts under the car.