Yeah , it is possible in any field of medicine , but as you know fully well , it depends on how hard you want to work and what the prevailing economic situation is. For instance, when I was applying for residency/fellowship in the early to mid 90s, Primary care /FM was the big thing because health care cost were going out of control , and gatekeepers were needed to curtail this. I guess as time went by and people/companies felt more will upbeat about their economic situation(also the threat of litigation towards HMOs) and relaxed these restrictions. The financial pendulum then swung towards the specialists and has been there since then.
I suspect with the looming cuts in reimbursement to physicians and the insurance companies writing letters to we primary docs about overutilization of certain tests, this will revert back to the mid 90s of the gatekeepers and annoying redtape. I remember the mid 90s how specialists used to cosy up to the PCPs for business. I think that if you are not going into interventional cards, you can still make something above 200k ,but you need to see a lot more patients in and outpatient. Weekends off at between 200-300k/yr? You must be very lucky.
Pray tell me sir, money is good and necessary , but if your decision of choice of specialization is primarily for money, you get end up being disappointed and unhappy . I wish you good luck , remember medicine is constantly changing and what is hot today , will be a no go area tomorrow.