I started with a used set of "NOVATRON" flash heads that used a power pack. They were very good and worked for just about everything I did. It was a complete kit that included stands and umbrellas power pack and three heads in a nice hard plastic case. I think "Novatron still makes full kits at a reasonable starter price. I now use Calumet traveler 750's and I really like them a lot. I had White lightnings but I sold them a couple years ago. They were great lights too.
Try E-Bay and see if you can get a set ofLights used at a good price. Go to search "Studio Strobes" I see what looks to be a kit for $275.00 that looks pretty good if you are on a budget. Using Studio lights will require a "FLASH" meter so allow for one in your budget. TTL will not function with studio lights so you will have to set the camera tomanual and meter the lights for proper exposure.