Company wants to steal my brand and domain. What do to?

Posted about this earlier but it was flagged, not sure why. Made some changes. I'll gladly edit to comply with rules.

I've been doing business under a brand and have owned the corresponding domain since the early '90's. Yes, I've been doing business under this brand since before the Internet went public and got the domain as soon as it was possible.

The brand was used in commerce prominently until about 2005 (manufacturing and selling product as well as consulting). I had a C corporation under the same name.

Around 2005 I shutdown the C corp and focused mainly on consulting with a few clients a couple of times a year. I operated as a "dBA" under this brand.

Because of the nature of this brand it has, over the last few years become very relevant to a market segment that is growing significantly world wide. I've been waiting for the right opportunity to get back into the game (design and manufacturing product) to take advantage of the new opportunities.

A few months ago individuals contacted me about buying the domain from me. It turns out they just started a company in another country using this root name. They offered me a paltry sum (a few hundred bucks). I told them I had zero interest in this.

Well, fast forward to today. They are now attempting to obtain a trademark in the US (I have a common law trademark spanning nearly 30 years of continuous use). If they are granted such a trademark I am sure it is their full intent to put as much pressure on me as possible to effectively steal my domain and trademark away.

These people have tens of millions of dollars available to them and have already stated they have no problem burning cash. While I don't have the financial horsepower to fight them long term, I have sought legal advise and will take a initial steps to mount a defense.

I'm sure there's someone on HN who's walked a similar road before. I'd appreciate any thoughts you might be able to offer.

No, please re-read the post. I think you missed important information.

I did not leave anything in 2005. All I did was shutdown my C-corp and continued doing business under a dBA. A binder full of invoices, etc. since early 90's until today.

No, I am not intent on suing anybody. I did not say that. I have not intention to sell the domain nor was I looking for this at all.

Short version:

    - I've been using this mark and domain continuously since early '90's
    - Not interested or looking to sell it at all
    - Company trying to strong-arm me into selling
    - Not a troll/hoarder...I've been using this internationally for nearly 30 years
    - Not looking to sue anyone, just want to be left alone

Do you have any interest in selling the domain and trademark to them? Perhaps you could give them a high number and they might say yes instead of a long legal battle.

This is moot, however, if you don't have any interest in selling to them.

To be frank, it would have to be one of those offers you can't possibly refuse. I hinted at that and they went from a few hundred bucks to a few thousand "last offer". Given their apparent mindset I don't see them going to a point where, on my end, it would be stupid not to accept.

To be clear, I am not interested in selling. I am simply describing what I would do in a hypothetical scenario where it would simply be stupid not to consider changing my mind.