storm7

The HC-800 is no longer available (unless you purchase one used.)
In the new controller lineup, you would want to look at the EA-3 or EA-5. 
What version of Director are you running?  The latest version (3.1.3) does not support the HC-250.
If you can describe your current system and upgrade goals, you can gather guidance on your upgrade options  
 

Agree with all that is said above. There are many great dealers on this forum who are incredibly knowledgeable and extremely efficient with their time.  I believe with most you don't have a minimum service call fee (like you would with a physical local dealer who rolls up in a truck) and just bill on the quarter hour.  I have found this remote dealer relationship to be fantastic if you are even slightly technically inclined and willing to do some work on your end (physical installs or using Composer HE). All that said, there are great local dealers as well but it nice to know you have some choices with Control4 which I believe is not the case with some of the competition.
I finally bought Composer last year but hands down wish I would have purchased it from the beginning as you can do so much yourself and save money.    If you are not aware the 1st time you buy Composer (from a dealer) the cost is roughly $150 but that includes your a year of 4Sight so you are basically getting the software for $50 which will pay for itself the 1st time you use it.
If your HC250 is on the latest 2.10.6 and you have the "Add Music" feature/driver installed you can add any of the Control4 supported native music services anytime you want.  There are a good number of them available with most of the major ones are supported in some form.  I ditched my Sonos connect boxes a couple of years back and just use Control4 equipment for streaming and it is great.  
 

I believe OS 2.10.4 was the earliest OS to offer the add music driver which enables the end user to add native Music  services without a dealer getting involved. 
 Also try not to get hung up too much on cost, once up and running it doesn’t actually require too much intervention. I would highly recommend HE and 4sight. 
 
If you do need a dealer there are ones on this site with Great reputations and also charge extremely competitive rates and some by the 1/2 hour.

agreed with what is stated above - also keep in mind, once you get moved in and set up, how often are you buying new tvs?  adding audio sources to rooms, etc?
You can always add audio apps on your own.  and with the IFTTT driver (which you'll need a dealer to install) you could easily tie in any device that works with IFTTT
Is there a cost, sure...but it is manageable once it is all set up.  And the remote dealers here can really set you up well at an affordable rate when required.

The cost of maintaining C4 depends on what you have it doing and how up to date you want it to be  If you are using C4 for AV and you just moved into a house then it may take a few hours of a dealer's time to set up all of your TVs, Cable boxes, AVRs, etc.  Light switches/dimmers take pretty much zero maintenance and don't get obsolete.
If you want to stay up to date and want to add new functionality from time-to-time, like adding voice functionality with Alexa, new music services, etc, then you are going to have to stay fairly current and update your OS every year or so.  That will also cost a bit of your dealers time.  Assuming that you want to stay up to date then certain devices, like controllers, touchpads, doorstations, remote controls, etc, may need to be completely replaced every decade or so as they become obsolete.  That will certainly cost several thousand.
C4 gives you very good, integrated home automation.  But it does take a bit of cash to keep the system current for both services and hardware.

I recommend buying HE. No, you cant add devices, but you can do pretty much everything else. Just remember to make back-ups. I've had my system coming up 10 years, and I've added to it greatly over the years.
Annual cost is the cost of 4Sight, periodic updates to the lastest OS, occassional addition of devices and equipment, and fixing what I buggered up in HE (I'm not a techie). 3 of those of course are completely dependent on the user and can vary from $0 to $x. I figure I'm averaging $500/year nowadays. 
If I buy a new switch, I've had the cost of install included (takes minutes) if  I do the programming myself to $10-$20 a switch. If it's fixing my messes, it averages around $100/hour, and it typically takes less than an hour with a good dealer: lots of them on this forum.