QiYi have recently released a new magnetic budget cube which may be pretty groundbreaking. The new QiYi Warrior 3x3 M is the cheapest magnetic 3x3 ever released and reviews so far have been positive, provided there are no issues with the magnets not being glued on properly (which I feel is unlikely because there is no way they can offer a magnetic cube that cheap without the production process being significantly automated).
The cube will be available in two options:
A regular magnetic option likely to be around £5-6
A UV coated version likely to be around £7-8
This will definitely be the cheapest UV coated 3x3 but also potentially the cheapest magnetic 3x3 and provided it turns well, it is likely to be a very popular choice for new cubers.
The issue is with the budget cube market is that there are so many good options that it is hard for a new cube to enter the market and be competitive, the MoYu RS3M 2020 has been the standard of budget cubes for 5 years now and has also been the best selling cube of all time on this site, but maybe with new technology allowing magnetic cubes to be produced for even less than ever before, a new budget cube can enter the market and be the choice for new cubers, to put it simply, you might as well pay very slightly extra for magnets now!