It's a sad fact of life that you sometimes you have to choose between doing what you love and getting paid more.
If the idea of specialising is really not what you want and would not give you job satisfaction then perhaps that's just something you have to accept.
There are so many choices in life and this is one of them. But even then, those aren't your only options. You can work towards a stronger management position or start your own firm, as many in your position have. But, again, perhaps those options don't appeal to you.
There is great value for companies in having a technical project manager who has enough breadth to see the big picture and make sure the end result is achieved but with enough specialised knowledge to make sure that the details are in order. Those kind of roles, however, are management roles. If you find the right fit of company then you can get a respectable salary and it can be a really fulfilling position because you get to see a project unfold under your direction, knowing that you actually earned the credit you recieve for it! (Unlike some project managers I've known who have next to no clue. Employing people who know what they're talking about it very important but it's just as important to know when you're not being told what you need to know!)
I suppose the question is, what's wrong with getting an average wage? Sure it's nice to get 'the big bucks' but it's up to you if you're willing to do a job you don't enjoy to get them!