Hard to beat a bk2 for batoning. 1/4" thick 1095. If you dont like the grivory grips spend the money on the micarta. Half of your required spend (w/ the grips) and you have a hellacious knife. I traded one off for a BK7 (another superb knife!) but i missed my BK2....so....i got another. The only knife ive ever had that i bought again...ive had plenty!
I love the BK2 as well, but given that he uses a Trail Master, I thought it might be too short for his purposes.
The BK9's blade is just 1/2" shorter than the Trail Master. Its blade profile has proven to be excellent for batoning for many users. The weight is almost the same as the Trail Master. The steel is high quality.
Overall, its value in chopping/batoning power per dollar is very high.
The other knives recommended here are awesome, but much of their advantage over the BK9 is in their suitability for other fine tasks due to the work that has been put into their design. For use primarily as a "belt froe" and less so as a camp knife, the BK9 is excellent.
If you're looking for pure bang for your buck on a knife that is excellent at doing the same job that you use you Trail Master for, I don't think you have to spend more than the cost of a BK9.