I owned a Baikal for ~5 years, shooting on average 40-50 geese a year plus a few ducks and what not, as well as some skeet at home for fun. Realistically I have put a couple thousand rounds down the tube of the MP153. First few years, it handled trap loads decently with the gas spring tightened right up and routine cleaning, but in the last year and a half or so, it would carbon up very quickly and would not cycle target loads, no matter how much cleaning and maintenance I did. I tried doing a couple rounds of formal skeet for the first time last year, and had to pound the stock to feed the jammed rounds (read: frowned upon). The nice thing about the 1187's is that you can change the o-ring and clean the action spring when it starts having trouble cycling, my friend has been shooting an 1187 for the same period of time and his handles target loads still to this day with some reliability.
I have since bought a Maxus and will never look back, but being on a budget I understand where you're coming from, I was in the same boat. That being said, unless you are going to stick to strictly 3" or 3 1/2" shells for hunting birds, I would lean towards the Remington. The Baikal is what it is, a rugged, incredibly dependible brick of a shotgun that will cycle every 3 1/2" mag you feed it for decades without so much as a wipe if you don't care to, but is not ideal IN MY OPINION for any kind of serious skeet/trap shooting.
If you want a third option, I would really suggest looking for a used Browning A5 or BPS or anything similar of quality chambered in 3", it should be more reliable in the long run than either of the your two options, my dad still has an A5 that I doubt he has ever cleaned, and has killed more ducks than lead-infested waters!
Edit: I just re-read your initial post, and if you are new to the sport, I wouldn't hesitate to pick up an 870 pump for your first shotgun and hit the range. You can start shooting skeet with strictly singles, no one will mind, and it will probably help refine your skills if nothing else. Re-sale will be exactly what you buy it for (if you pick one up used), tho you probably will keep it as a back-up till the end of time, my wingmaster has served me well for the days I got sick of jamming my Baikal with target loads, or someone else forgot their shotgun or key for a trigger lock.
