Using GarageSale Version 7.0.13 (827), macOS Version 10.12.6 (16G1212)
The Smart Group filter for “Buy It Now Price”, “Starting Bid” and ALL number fields are too small. Many Prices and Category Numbers are 5 digits or even 6, plus a decimal point and comma ($1,999.99).
In GarageSale 7, we are using the system’s predicate editor view, whereas in GS6 the complete panel was home grown.
The narrow number fields are indeed Apple’s default UI for number properties.
We’ll look if/how we can make those fields wider, but that probably would include a fair amount of hacks, that might break with the next macOS release.