There's a few things you will want to consider before deciding on a recast as your first. My answer has always been no, even when I was a pro-recast supporter. Here are a few things I thought of when I was into recasts and a few thoughts after I left that part of the hobby. This is just my opinion, it's not gospel, and I'm not billing it as anything other than my opinion and experience. Your mileage may very of course. Yes I'd like to sway you towards buying legit instead, but I'm also objective enough to see the good points of recasts.
I'll probably update this as I come up with more ideas or change opinions on things. XD
Reasons you might want a recast for your first:
For example: Magic Time bjd makes an MSD with a body IDENTICAL to the minifee body minus magnets, it's not banned on DoA (I asked), and they make a head that looks amazingly like a Chloe. This doll is barely more expensive than a recast minifee Chloe.
See my answer to Reason #1 above. Additionally, keep in mind if you're using proper materials you aren't going to ruin a doll. Seal, don't use oils or sharpies, and you don't need a "practice" doll. I never had one myself.
Reason #3: Company doesn't make the skintone/resin color I want.
Hybrids aren't something newbie collectors need to be worrying about, imo. Hybriding can be an overwhelming process, and you can never be 100% sure that the head will even fit on the body unless it's a hybrid someone else has already done. My recommendation is to start with a full, inexpensive doll, or save up for that expensive doll you really want. Having your first doll full and complete is a great feeling.
So what if you can get away with it? Generally, it's considered rude to break the established rules of a community, and you'll find yourself the center of drama, ostracized, and banned if (when?) you do eventually get caught. Most people really don't care what you own on the side, so just be respectful and don't post recasts where they aren't welcome.
Reason #7: The doll I want is no longer made or sold out!
Accusations of racism are something I'd investigate yourself rather than just believe 100%.
Reason #9: I don't like "cheap" companies, but don't want to shell out for a Fairyland.
Example: I'm considering a mini supia, soulkid, or Magic Time body for my incoming minifee Soony head. Yes I'd love for her to have a legit FL body, but it's not going to happen for a long time.
Reason #10: Anti-recasters are loud, obnoxious bullies, so I'm going to be spiteful and buy recasts.
Thing #1: Recasters fuck up. A lot. Most recast orders get something wrong, and I'm saying that from experience. I was pretty lucky to only have a few issues, but for every good order there were at least two or three complaints. Recasters often get bodies and hybrids wrong, wrong skintones (especially with tan), send wrong sculpts, forget parts, etc.
Usually the quality is still good, but in order to get your missing parts you'll have to piggyback on someone else's order or make another order and hope they don't forget again.
Playing Devil's Advocate, you can avoid most of the hassle of dealing with recasters by purchasing second hand recasts or joining a group order.
Weak resin is another risk. Many of my recasts ended up with pinholes from weak resin, cracks, breakage, etc.
While it is true some companies can have this issue, I'd never run into a recast that didn't require effort to get it ready to go, and I've had lots.
Thing #8: Special Snowflake (aka a bad reason XD)
Thing #9: Quantity?
Is a large collection or small collection more appealing to you? Do you want an army of minifee or Iplehouse? Why? Popularity, status, just because you like them? If quantity isn't an issue or you don't need a massive collection, it may be worth it to save up for legits for better experiences and quality overall. If you just want a big collection of cheap dolls (e.g. cheap minifees) then maybe recasts are the way you want to go. Just be sure not to use the "I can't afford legits" excuse if this is the case.
List of posts that might help:
DoA's under $300 List!
My Newbie's Guide to Fairyland
FAQ's and other useful information