I'm so sick & tired of non-answers from one particular massage practitioner who doesn't have anything concrete to offer except her own services that I've spent time gathering REAL figures for you.
I am assuming you want to open a practice for one person (you), working 5 days a week. I did the same thing 4 years ago and spent around $8,000. Here's what I bought:
Electric table, $1,500
Table accessories (heating pads, bolsters, breast pillows, pregnancy pillows, neck rolls, etc) $500
12 sets of very nice 800-thread-count linens, $650
Set of hot stones with warmer, $100
Paraffin bath and wax, $150
4 gallons of lotion with holsters from Biotone, $200
Cleaning supplies (vacuum, dusters, gallon of Simple Green) $250
Computer and nice speakers, $750 (I use free online music and scheduling/billing software, links posted below)
First & last month's rent with deposit, $2,000. ($750 per month rent plus $500 security deposit)
Marketing (business cards, web site/Google keywords & maps, yellow pages), $500
Misc furniture and accessories (tables, chairs, decorations) around $1,000
The first space I rented had 3 treatment rooms. As I added therapists I outfitted each room for about $3,000 each. Then I added laundry facilities for $2,000, including plumbing and washer/dryer.
I bought very nice things that would last a long time. I have a friend who opened her business for $1,500 on a single room buying the cheapest used stuff she could find, but she's already replacing things after 2 years. In the long run it's best to buy good stuff.
Good luck to you!