Well, l love the 1377 and it is way under your budget. It needs a few little mods but they are easy things. If you don't mind a multi-pump and a small amount of noise, it's a good one to consider.A bargain low-powered pistol that will be very low noise is the Baikal IZH-53, for about $56. This is a springer pistol and does not develop a lot of energy (I haven't explored what might be done to improve that) but it is well made and very accurate. It is a large handgun (with no safety) but not excessively heavy, and good quality. People in the next room wouldn't know you were shooting it. I am surprised these don't get more discussion- good pistols at an amazing price. Anyone considering one of the "Westlake" or similar Chinese 19.95 pistols ought to get one of these instead.My other favorites are over your budget. The closest would be a used P3, or HW40. They can be found in classifieds for $125-150. They are marvelous, with excellent triggers. There is a cheap clone, the P17, that I had terrible luck with, but some people like them. The P3 is still my favorite hand airgun. I have a P5 and HW45, but will generally grab the P3 for a quick fix. A used P5 can also be found in the $150 range. Don't believe the 700 fps nonsense; I don't think it would even do that with PBA pellets. They are nicely made but I hate the safety, and the ergonomics aren't as nice as the P3. They have a lot of torque and recoil on firing but have nice barrels.
The 1377 is a good choice, though I confess I have never owned one.IMO, any CO2 powered pistola is going to have a pretty good "bark" for back yard suburban shooting. My favorite plinking air pistols are the single pump pneumatics. The Beeman P3 and the IZH-46m are both excellent choices for single pumpers, but both are above your stated budget. If I were only going to have one air pistol, it would be the IZH-46m, though. It is the most accurate air pistol for the money, has a great trigger, is very quiet, indoors or out, and can take you to a level of target shooting that will only be exceeded by pistols in the $1000 and higher range.
How about a 2300 from the crosman custom shop
also, you dont necessarily need a 747, as its cheaper sibling will do just fine. as per numbers, the 7x7 series pistol will out shoot in fps the mighty p3. The p3 shoots 402 fps with rws hobbies (7.0 gr). A WELL ADJUSTED 7x7 shoots an average of 409 fps with JSB RS 7.3gr. Both run two 20 shot strings back to back and then average. I did replace grips on mine for ambi wood furniture, and i am using a b square mount to attach a 2x20 pistol scope. very accurate gun, sturdy, reliable and consistent...