I've used GODaddy to register a domain and their service is good. Cost $17.90 for 2 years, or about €14 at the time.
For Hostimg the domain I was recommended (and use) UCVHost www.ucvhost.com/ which costs €25 for 2 years, about €1 per month. They have a very usefull Stats facility (AWSTATS) that comes with the hosting, for free, (maybe all hosters do) that allows you to see the number of hits to your website plus a whole lot of other info (e.g. what search words and engines they used to find your site).
1 thing that I was recommended to do, and appreciate the advice, is to create a new email account for use when registering the domain, because unless you opt for privacy (which costs more) you will get loads of emails offering all sorts of web services, i.e. spam.
Feel free to visit us at www.corktango.com or if you are into Tango, and in Cork, drop in.
Cheaper ie..................not that I am aware of. .ie is probably expensive because it's Irish supplied........tongue in cheek.
Although there is extra criteria involved when registering (business registration / fax of your details and reason for registering etc.), it still doesn't, in my opinion, justify the inflated cost.
This has a list of all the approved domain resellers. Some of these may give you a discounted registration price - especially if you host your site through them
I use www.register.ie ( you can check domain availability here as well) and have a domain through them, great service when required ( a little dearer - Eur18 a year for a .com) but worth it. They also have a service called "email lite" for Eur18 a year - catchall email service for low use. No complaints about them at all.