Yes I did reply 16 years or so later but may I ask what budget subs are you relating to because you are wrong about how long this sub can last a friend of mine has a klh Asw10-125c and it’s basically around the same age his sub is still going strong I had another budget sub that this sub actually comes close to its performance I had a bic formula f12 400 watt sub and my Samson sub is still going strong and despite its 120 watt power rating its near the performance of the bic and my friends klh sub same power as the Samson basically shames the bic f12 power as the Samson does too.
This wasn’t for me since i didn’t mention longevity, but Ime pro gear usually lasts a long time. It’s built to be banged around and take so I’m not surprised you’ve had it so long. Also. Power ratings in subs aren’t that useful since it doesn’t take overall efficiency of the subwoofer as asymptomatic system into account. It’s probably not bad for smaller rooms where playback isn’t super demanding.
As far as budget subs go, that’s complicated since everyone has a different level of disposable income, and what some people value, others might not. For me, a budget subwoofer is something like the rsl speedwoofer 10s. Iirc it comes in at 450 bucks. It goes down to almost 20hz and is very linear. BUT, it doesn’t have nearly the output of its big brother which is also twice as much. For others I might recommend a budget sub like the aforementioned BIC, or one of the Dayton SUB series. i don't normally think of pro subs for HT use, but recommend and use pro amps for speakers. So like most things, ir depends.