Hi Amanda!
I am a pmu technician. I would 100% suggest training in machine method as well as microblading. These 2 day courses in my opinion don't cover PMU sufficiently, to enable you to do either well enough and without any problems post treatment. This is where the issue is. Anyone can microblade, it's not hard. However, not everyone will understand technique, colour theory (as it's nothing like regular colour theory) and how to deal with any problems that occur. Also, as a hairdresser you probably haven't covered anatomy in the depth that PMU should require. Unless of course you have studied beauty therapy level 3 also.
In short, it would be like me going to study hairdressing for 2 days as a beauty therapist. You would think I was mental. The difference is, a crappy hair cut, scissor wound or reaction to dye is probably the worst that would happen. With PMU you can scar someone for life, give them brows/lips/eyeliner that looks horrendous and then either get sued or pay stupid amounts to rectify with laser removal. I had someone only yesterday who has keloid scarring around their lips from old pmu.
Don't let this put you off, but I am just telling you what I know having paid a lot to study it. It's a great job, I really love it but at the same time I also have days where I hate it. I sometimes go home in tears and worry about retention or nightmare clients. £325 might seem like a lot but after two treatments and product use, travel (if you do it) plus the stress, sometimes I feel like it should be more like 1000 before I even look at a treatment enquiry haha.
If you decide to go ahead please do look for courses that are at least 5 days and provide models for you to work on under supervision. Also make sure your trainer has at least 3 yrs experience and teaching qualifications. If you decide it's not for you, why not look for someone to rent a space in your salon. You'll make a nice little income without any hassle whatsoever.
I hope that has helped. I can put you in touch with excellent PMU trainers throughout the UK if you do decide to go ahead. Just give me a shout.
All the best!
Asher