P3RS1AN, the decision how much to spend will depend on how much they pay you and for how long you plan to do the work
How much time do you have to get the tools?
If you have a little bit of time:
1. Tool Cart - I would recommend buying used. Sometimes you have good deals on good brands. Harbor Freight is around 290 for 5 drawer one if I remember correctly. Check local CL, Faceook Marketplace, etc...
2. 17, 19, 21, 22 sockets in 1/2" socket set - Look for great quality used prior to buying new. Sometimes you can get good deals, especially if the tools are initialed, etc. Try to find Snap On. Consider SK. Can consider looking at prices of Koken - will end up buying new though - used are hard to find.
3. I assume you will need 1/2" ratchet - look for used good quality one. I think SK could be a good start - I see them used and new sold for not that much (I remember seeling new one for $40 myself as I had another 3-4 vintage ones). Also can check other quality brands depending on what's available in your area.
4. 3/8 drive set - I am not sure if you will need the whole set. Check with your dealership. You might consider buying the sizes you will need the most to start. As before, consider good deals on used ones. Watch the video below
5. 3/8 ratchet - SK, Snap On (I would consider looking for a used Snap On - get them below $50 on CL periodically. Right now I see them $70 (but marked) listed for a while... Do not forget other older brands - one of my favorites now is an old New Britain which I got couple of years ago for $2 which needed deep cleaning and lubrication.
In general, Snap On or SK are a great choice long term if you find a deal on ratchets
6.Torque Wrench - you are not going to do high precision work most likely - consider Tekton. Keep looking for good deals and upgrade (NB if your shop provides help with torque wrench calibration at discounted prices or for free - I periodically see Snap On and other good quality torque wrenches for reasonable money used...
7. Basic Metric Wrench set - again, try to figure out what sizes you need. Depending on the place where you work and amount of rust you might see, consider possibility of 6 point combination wrenches for common sizes which you expect to use a lot.
... the oil filter removal tool - I think there is a thread here somewhere - do not remember which one was considered the best. Ask the guys in the shop as you will be using it day in and out.
If you are in a rush and need to get a lot of things fast.
-If you have Home Depot nearby - just get some basics (I think Husky still has lifetime warranty on sockets), Gearwrench ratchet, etc. - if things break, you can just swap them fast... And then keep looking for great deals for tools which you use the most and slowly upgrade...
I hope this helps
Sorry, I am a DIY - a pro might give you a better advise, but this is how I would do it
Watch this videos:
- will help you with common sizes!