Re: Not really the council's fault
This smacks of procurement incompetency.
You will find (and should only select) solutions where there is a reasonable field of competition. This starts well before a tender is issued, speaking to a variety of prospective providers about their solutions, speak to peers in other public sector about their solutions, finding out about the good, the bad and the ugly. Seek references from the supplier, but also do your own homework.
Then you let all the prospective providers know you will be coming out to tender. Give them plenty of time, give them an indication of scope - even get suppliers' feedback, keeping an open mind (you never know...).
Don't issue a tender until you know that at least 5 organisations plan to respond. You may well get some unexpected responses, but the ones who engaged early with you will know you (and you will know them) - a clear advantage.
Have a firm idea and a tested methodology to evaluate price and quality. Ask for reasonable and realistic things, be clear. Give scope for value adds. Don't try and devolve all the risk to the supplier, because less risk for you means higher prices.
By that time you will hopefully already know who you might want to work with and a tender formalises that process. Yes, there may still be surprises, but then the surprise may be a lower price or an innovative value add.
A bit of time and effort prior to the process starting will well be worth it.
(I have been a poacher and a gamekeeper in public sector procurement and know that it CAN be done well - with good outcomes)