I have different hors d'oeuvres menus and stationery menus for different price points.
Food costs are 20% of food proposal, plus staff costs ($30/hr incl grats and a $50 penalty if they accept the gig and arrive late), plus rentals (I work with a company that gives 15% on referred biz) if you don't already have your own collection of wonderful trays/platters, plus tax and grats.
Generally for a modest finger food/HD menu, it runs about $3. per selection per person. So with 6 selections, it's min $18pp. (then rounded to $20 for cocktail napkins, skewers, garnishes/flowers). That menu would be canapes, easy/quick phyllo combos, bruschettas, "gourmet" meatballs, fried polenta cubes topped with XXX, scalloped cucumber cups filled with XXX, stuffed mushrooms or cherry tomatoes, mini pizzas or quesadillas.....sometimes I'll include a tuna tartare which has a high yield for very small portion on fired wonton chip. There are so many ideas on the Cheftalk board on inexpensive HD that you can do that are not labor intensive.
I like to do more upscale selections and charge betw 5-6. per selection, per person.....crabcakes, 16/20 count shrimp, oysters with "pearls", scallop ceviche, B&W sesame crusted tuna, filet mignon skewers with ancho chili rub with espresso dipping reduction, coconut curry chicken skewers served with fondue presentaiton. Prefer to start at $35.pp. For a 30th BD for a 2hour cocktail party then following with sweet finales which might run another hour of service....you can do so many variations. For 150 people with passed HD, I would schedule 6 waitstaff, 3 bartenders, 1 chef, 1 asst. (add time for set up through breakdown and cleanup)
Running the numbers really quickly, I would be charging betw $4000-6500 exclusive of tax and 20% grats. Just my personal thoughts. Good luck.