Can you use the upgrade costs on page 240 to build a custom commlink at character creation? I bought signal and response upgrades from 1 to 5 and came to the price of 9,960 for a R5/S5 commlink.

Can you purchase a commlink this way, or is that list purely for upgrading a preexisting device?

Some of the upgrades list a price and an Availability, thus they're within the confines of the limitations for character creation. As always, ask your GM if unsure as individual GMs may have their own opinions on such thing.

Personally I allow it.

I see no reason why you couldn't purchase a commlink in that manner.

The only reason I'd consider not allowing it is that it seems to render stock commlinks beyond the Meta Link pointless. For 5,000-nuyen you can upgrade one to Response 5 and System 5, which is better than the 8,000-nuyen Fairlight Caliban (4/4 respectively). Well, unless you assume an escalating cost, where you have to pay for 1 to 2, 2 to 3, 3 to 4, and finally 4 to 5. But then you'd probably have to assume that for all things in the game, including stock commlinks. :/

I usually allow it for characters who are intended to be savvy about technology and not necessarily just hackers, chaos mages (for example) would also probably build their own machines, too. For characters who aren't tech savvy, the stock commlinks in the books are a good purchase for them.

I figure if you want to go that route, I'll force you to make the rolls to do it at character creation. Without using edge. Because you supposedly did it yourself, no?

Personally if my players want to start with custom spells, broken copy-protection, ect I allow it if they have a large enough Dicepool to buy the necessary hits, Edge included because I figure that the characters don't just wake up the day the campaign starts and say, "You know, I feel luckier then usual today."

...Violet started with the MetaTech M5-TX, a 5/6/6/5 link (Response/Signal/Firewall/System) which I built from the upgrade rules to reflect it being an experimental model. Interfacing with any external devices (firearms, visual/audio augmentation etc) is done exclusively via skinlink

The M5-TX is also implanted and hardwired to a datajack (originally for diagnostic purposes) which makes it very useful for downloading to offline storage or jacking into that occasional hardwired port on isolated/shielded systems.

It it's time (2066-68), it was the hottest of the hottest in wireless links, akin to say having a present day top of the line notebook three or four years ago.

She has since had the Response and System upgraded to 6.

Violet sold the design concept to a competitor (after backwards engineering it through the internal diagnostic systems) in exchange for her extraction from the MetaTech corporate village and a new identity.

...needless to say, MetaTech is not very pleased with her.