Location has an ancient Meridian 616 with DR2 and 14 phone sets (7208 & 7310 mixed)

Need to add the IVR we manufacture to his system.

Method?

Upgrade to DR5, add 4 or 5 ATAs and show him the final invoice?

Swap cabinet for an 8x24, add the analog card, cost effective?

Any other suggestions?

Trying to keep them from getting a $2500 charge for having our device installed.

All help is ALWAYS appreciated.

it's all tip and ring