Hey Mitch,
I agree with you regarding the Omron MX2 or Hitachi WJ200 VFDs, these are excellent VFDs used in the industry. They are very smart and state-of-the-art and not comparable to the cheap chinese VFD crap. I would also always think of the Invertek Optidrive E-3 since it is produced in the UK (not only this means that it is not produced in China, but I think the UK manufacturers need our support more than ever).
I also agree with you that the Mechatron 2.2 kW 80 mm 24,000 rpm ER-20 (Specs) spindle is not cheap, and at the moment I cannot tell you if it is worth the money. But there are at least three other forum members who own this spindle and have experience with it, who could tell you what they think about it.
But you have to know that the very cheap chinese spindles are very cheap, i.e. they have poor efficiency, are noisy and their bearings probably wear out faster. There may be differences though, I have no experience with them. There is one forum member who has combined a good VFD with a cheap spindle, the Hitachi WJ200 and a cheap chinese air-cooled spindle, as presented here and here.
But what other users have done, finding the Mechatron and other german industry manufacturers too expensive, was not to buy a cheap Chinese spindle, but a more expensive Chinese spindle, namely a Jianken. I have no experience with this, but others here on the forum do. For the price of a Mechatron without ATC you can get a medium-expensive Chinese Jianken with ATC, which can be seen at work here and which was presented in these posts, and for a medium price you can get a Jianken without ATC with 80 mm diameter and ER20 collet. It is worthwhile to look at this direct comparison in terms of vibrations, between a cheap ebay spindle vs. a Jianken spindle (video) (shown is the JGL-100 2.5kw 24000rpm ATC with ISO 25 taper).
Please be warned that when comparing the power (kW) specifications of the Jianken spindles with European spindles or other spindles, that the Jianken power ratings are not IEC 60034-1-compliant! So if you buy a 2.2 kW Jianken like the JGD-80 2.2 R24, it is in fact only a 1.5 kW spindle and not a 2.2 kW, as explained here. So be aware that if you want to buy a Jianken spindle that has the same power as a Mechatron HFS-8022-24-ER20 that is rated 2.2 kW as per IEC 60034-1, you would need to buy a Jianken 3.2 kW spindle!