yes it is a good idea to get a good dedicated sound card if you are buying a nice headset or a nice sound system. Not only does the sound card, noticabley improves the quality of sound, but later if you want to upgrade to a good $500 5.1 system or something, you will have the option of digital or hifi sound, and if you love sound and love blasting your music on full and love to drive your neighbors crazy( if you live in an apartment like me, the neighbors got fed up and just covered their wall with soundproof material lol)
anyway, 50-100 bucks willl get you an great sound card and its totally worth it. my sound quality really improved after i switched my audio system from an intergrated creative soundblaster X-FI on my $300 dollar motherboard (fancy motherboard, fancy intergrated sound card, i though the intergrated card ion this mobo was just as good as any dedicated card) i was wrong. i got myself an ASUS Xonar D1. the thing is great, it destroyed my intergrated creative soundblaster X-fi, It was like as soon as i git my Xonar D1 installed, and started playing music, i hear a pop and smoke comes out of my comuter, i open it up, it was the intergrated audio chip that blew up because it was that jealos of my Xonar D1. so it like died of jealosy lol.
Anyway it should be from 50 to 100 bucks, as far as i remember. but i bought it last year so it might be even cheaper now.
Now there are cards out there that are $100- $200-$500 Sure they are powerful, but unless you are going to buy some totally kickass active sound systen ("active" means with a dedicated reciever) these systems cost $700 and above. Or if you actually work with sound do recordings and stuff, dont bother buying a card above $100 bucks. Now my soundsystem is called a "passive" sound system where a reciever is built into the subwoofer, and the system just plugs straight into your computer soundcard withought having to go trough analog to digital converters or that stuff. so mine is like one of the best passive sound systems on the market. I got it for $500-600 and i have an ASUS Xonar D1 to go with it.
so depending on how good your earphones are, you could always get a cheaper audiocard for less than $50 bucks, it might not be as good as some of the more expensive 4 channel audio cards, but it will definatley be better than your intergrated raletek sound device
look on newegg for a decent sound card. trust me a good sound card is worth it, No matter what people say, sound is always extremeley underrated.
one of my computers has a an ancient 5 channel home theater sound card (with a front panel sound controller

) from late 90s the thing was extremeley unpopular, it didnt even have drivers that supported win xp because there was no win XP during that time. Even tho it was kindof buggy, i got it to work And even this 15 year old piece of crap made my 15 year old speakers sound really good way better than the intergrated soundcard on my motherboard
dont hate people who rip you off,cheat and get away with it, learn from them