Need Venue Suggestions for Surprise Birthday Party

Call some actual restaurants. For example, Blue Mesa only charges $50 for a room (on weekends only, weekdays it is free) because they make their money off the food. If you do a buffet with a variety of appetizers it can be about $12 per person with non-alcoholic beverages.
So, call a few places that have party rooms and see what you can work out. Maybe a minimum food purchase would equal a free room or extremely discounted room price. Some places that are pretty neat, but not sure about the rooms:
Brewed on Magnolia, Live Oak (we had a huge dinner for my friend there and they let us eat in the performance area since no band was playing), Blue Mesa on University, MiCocina, and Central Market (they have that big patio area and depending on weather could be a LOT of fun and affordable since you can purchase food/drinks inside and simply walk it out and serve:)
Have fun!!
FYI: Not really sure what your budget is, but you mention a $350 price point. I really don't think that is realistic. I have never seen anything for less than $8 a person and the reality is after drinks and 3 -5 pieces per person (appetizers) the average cost is more like $15 a person.

you might also check with the city community centers and recreation centers (like the Y)- they might let you rent one of their rooms and bring your own food in. You could also check the website for the Chamber of Commerce. They might be able to tell you the restaurants that could accommodate a group of your size. When is the party?? You might also call a local restaurant that is closed during that time and see if they would be interested in a private party.
Good luck. If you get to bring your own food, check out Costco-they have some great party foods and trays.

Lake Arlington Baptist Church rents their Fellowship Hall and it would be around $250. $200 for the Hall and $50 set up/clean up fees. Give me a call at the church office M-Th between 8:30 and 5pm @ ###-###-#### x138. I go to lunch at 12:30.

Spring Creek BBQ has a room at the Arlington and Mansfield locations.

Hope this helps.

P.

Just had a surprise party for my husband the same time of day and boy did people eat. London broil,mchicken Marsala, Mac n cheese vegies, rolls, salad, meatballs, ziti, a cake that was not to be believed, appetizers, brownies and cookies. I would hit Costco or BJs for food. You can make finger sandwiches, pigs in a blanket, little spring rolls, chips, dips and nachos, chicken wings. Whatever you decide,w just have enough. That's a lot of people.