Catering costs?

Olive Garden does have catering options for weddings. Just by going to their website you can look at pricing/serving for different items.

https://www.olivegarden.com/menu-listing/catering

Catering costs depend on your area. I've had Olive Garden corporate catering and it pretty tasty. It may be more universally appealing than bbq, depending on your crowd. Or bbq may be more appealing. Ask a small group of your guests.

The costs are pretty straightforward because they do not nickel and dime you for unnecessary additions. If you have 100 guests, their menu says it costs $x then that is all you pay. Pretty simple.

Have you considered reaching out to a locally owned restaurant? We plan to use a local place and will hire a local bartender or server to take care of setup, serving, maintaining, etc., but we are also only having about 40 people max.

You can hire staff through event staffing agencies on thumbtack.com and still com in cheaper than a wedding caterer.

Corporate catering by local restaurants whether Olive Garden or the local bbq is perfectly fine if it fits your vision and budget. However very few if any employ enough staff to allow for anything other than drop off service where you have to find your own staff.