Honestly, if you're new to swordsmanship, I highly recommend getting a feder of some type first. If you want the most "sword-like" feder possible, I highly recommend looking into Purpleheart Armoury which is based in Texas and their Technique feder line which comes in a variety of pommel designs at a really affordable price of $220 at time of writing:
I also recommend their Fiore Feder if you got some extra cash ($269 at time of writing) and want a nice blunt sword/feder that can be easily fixed and disassembled:
If you're really keen on getting a sharp sword on a budget though, look into Ronin Katana who's also based in Texas and despite its name also has a really affordable and well-built medieval line of sharp longswords that range in price from $275-$450 (but can be cheaper if you don't mind some minor aesthetic issues on your sword and keep an eye out for their annual scratch and dent sale that usually occurs in spring).
Other companies that produce decent budget sharps to mention are Cold Steel, Windlass, and Hanwei.
Let's start with CS; some of their swords are clunky and not great, but their Italian longsword is ubiquitous, reviewed by many, and is pretty decent given its relatively cheap $250-$300 price point if you look around on Google for it.
Then there's Windlass. The only bastard/longsword I own from them which I would recommend is no longer available on their website but is available on Kult of Athena, the Sword of Roven. Admittedly, it is a bit big and clunky for a so-called "bastard sword" and more of a true two-hander, but it is decent for a sub $300 sword and pretty good bang for your buck.
Finally there's Hanwei. Hanwei's Rhinelander Bastard Sword is in your price range, is found in various places for about $250-$300 and Matt Easton reviewed it. What's unique about it is that it's one of the few production bastard/longswords out there that has a sidering if you're interested in that type of sword but it seems to unfortunately quickly go out of stock at time of writing.
One final thing: if you really want to have your cake and eat it too on a budget (i.e. a sword that can be both sharp and blunt at the same time with a simple unscrewing of a nut and a bit of work) look into the Hanwei Tinker Pearce blunt longsword and purchase a separate blade for it. Yes, there are people (who usually are also the types to brag about the number of Albions or Regenyeis or whatever they own...) who have criticized this sword, Hanwei, and their somewhat spotty quality control, but if you're a beginner who has only worked with wasters/synthetics and are on a budget for swords (which OP seems to be given his $400 limit), I can see the appeal of this sword as long as you don't plan on using it for heavy sparring. For someone who is unsure about having to dump about $250-$350 or more twice on both a good feder and a good sharp longsword (which you honestly need both of if you want the full sword experience) it's just more cost efficient to buy that sword and a separate cheaper blade that come out to about $470 or so with shipping on Kult of Athena. Say what you will about quality, but money saved is money saved at the end of the day and swords are not getting any cheaper especially given the supply chain problems we have nowadays...
But, maybe those issues I brought up are not a big issue or something for OP. Maybe he just wants a sharp and is fine sparring with his synthetic and doesn't need a feder. Maybe he's OK with owning just a sharp and lightly moving it around for drills and doesn't plan to be doing any sparring or risky things with his swords. Maybe he can get more cash and buy both a good sharp and good feder. Maybe he can get a sharp, blunt it for safety, and then do some test cutting drills with it by cutting easy mediums like fruit or clay or something to safely and enjoyably experience what test cutting is like with minimal chance of injury to self or others. I don't know what OP wants and how owning a fully sharpened and functional sword will help him accomplish what he wants, but I hope the above suggestions help with his very important decision of buying his first steel sword because all sword enthusiasts have been there and for better or worse you never forget your first if you know what I mean... :P