Depending on which country you learned in, you will need to get training on UK Accounting, but your experience will help you 'in the field' so to speak.

I understand wanting a 'cheap' course, but what you must bear in mind is what is appropriate.

You may start the AAT and feel like you're not learning anything. You would be best communicating with the applicable accounting bodies - whether AAT, ICAEW (for ACA), ACCA or ICAS (if you're in Scotland) and seeing what's appropriate.

It may be that you could do a more expensive course, but gain exemptions due to your degree, but I don't know what credits you can get for an overseas degree (outside of my area of knowledge, I'm afraid).

Then once you've determined the qualification that meets the aims that you have, then you will need a training provider, and the bodies should be able to advise you accordingly.

If you want to build a career in accountancy, then sometimes taking a training position with an accountancy firm is the way forward as they may pay for your fees and give you time off work to go to college while you're studying for qualification. Do some digging on training providers or firms near you. This does provide stability of income while you get qualified.

I took this last route, rather than attempting to fund my own study and hold down a job, so can only speak from my experience of that.