I have owned and used several Dual TT including a model 1229 changer (rim drive) and a model 601 single play (belt drive). Today, unless I was trying to assemble an all-vintage system I don't think purchasing a used TT, even a good one, that is more than 15 years old is the best way to get into vinyl.
Turntables, more than any other component, must be carefully packed before being shipped. These days that probably means without the benefit of the original box and packing materials. Turntables are precision devices that have tolerances that can wear out with age and use or are easily damaged in shipping. Also parts, while available, are getting pretty pricey for some models. I.e, the replacement rubber puck that drives the rim on a Dual 1229 or 1229Q is $65 last time I checked.
Buying a new, low end consumer turntable, as you did for about $100 to try vinyl was a good way to start. As you have noticed, vinyl (especially used vinyl) can have lots of surface noise from dirt and scratches. A good record cleaner would be a smart follow-up purchase, as you continue to search used record bins and garage sales for decent vinyl copies of favorite bands and albums. When you have assembled a decent collection of vinyl albums then it would be time to consider upgrading your turntable and cartridge. Something like the Music Hall MM3 can be had for about $500. This would take you to the next level without the headache of repairing, sleuthing for long out of production parts, and restoring an older turntable to serviceable condition.
That being said, if a nice Dual 1229 or 1229Q showed up for sale for under $100, and I could just carry it home with no worry about shipping, I might be tempted. But it would be with the understanding that it was going to take some time and money to get the unit back to proper operating condition. FYI, one of the reason the Dual TTs are popular with music lovers who are also musicians is that these TT usually have a pitch control. This is normally used to set the speed to exactly 33-1/3 using a strobe disk (also some later models had the strobe markings along the outer rim of the platter) and a fluorecent light source. Musicians can use the pitch control to tune the pitch of a recording if it is slightly off so that they can play along with their own instrument and still keep in time with the music. It was not unusual for records to be slightly off pitch when recorded.