Soldering iron : If your Weller (good choice) is a temperature controlled one, i.e. it takes tempareature controlled bits, then you don't need the soldering station apart from a stand with a solder sponge. Recommend a PTF7 bit for PCB work. It's a fine bit. If you need something a bit bigger then the PTL7 is the one to go for. If your soldering pump is any goos then put the solder braid in a draw and forget about it.
Tools: The following come under the heading of highly desirable and dead handy to have around but you don't need them all right away.
They ain't cheap but properly used a set of Lindstrom side cutters are the bees knees, Use them for cutting component leads, hookup wire and nothing else and they will last a lifetime. I have a 40 year old pair that are still good. A cheaper set of end cutters are useful too. A scalpel or sharp craft knife for cutting pcb tracks. Small snipe nosed pliers, the ones where the nose is about 2cms long. A small electrical screwdriver (a must have) for knob grub screws, terminal block etc. A set of watch maker's screwdrivers. A set of Allen keys. A set of Torx drivers or at least a few, especially a tiny one as cell phones tend to be held together with them. Tweezers. A stiff brush and an aerosol can of pcb cleaner. A fibre glass typing error correction brush can be handy too. A reel of 60/40 multicore lead/tin solder. Do NOT get lead free solder, it's a mare to use even for the experienced.
Large electrical pliers. Large side cutters. A set of BA or metric or both nut spinners from 0BA to 8BA (0,2,4,6,8). A set of BA and metric spanners in the same size as the nut spinners. The list is practically what a professional service engineer would use so as I said buy the bits as and when you feel you need them as they aren't all required initially.
PSU: Ideally a 0-30V variable power supply, which could be your first project. Mostly a 12V and/or 9V regulated power supply will do for starters.
Function generator/signal generator. Depends on what you are doing, audio, digital or radio. My first signal injector was a home brew 500-1600KHz rf oscilator modulated with a 1KHz sine wave. Basically a two transistor wonder which would inject AF and RF into a circuit so ideal for fixing AM radios.
DVM : €4???? I wouldn't rely on it too much. An analogue meter is a handy thing to have a round for some jobs.
Scope: Definitely a useful beastie to have around. The higher the bandwidth the better. For scopes, signal generators and other cheap test gear keep a look out for amateur radio rallies or hamfests where there's usually a bring and buy table where you can get cheap test gear provided you don't mind it being a few generations old and what some snobs call a "boat anchor". I had a Tek 547 100MHz b/w oscilloscope which I got for about €60 at a rally, although it did take two of us to shift it to the car http://reviews.ebay.com/The-Tektronix-547-Oscilloscope-Magic-in-the-Box?ugid=10000000000725321
Where to start. Try a few small cheap Vellman kits to start with and see if you can get them going. You can then decide which way you want to go as far as projects are concerned. I tend to gravitate towards audio (guitar effects) and radio but a lot of people tend to go for 742,841 ways of turning LEDs on these days. You can also get into stuff like making bits and pieces with an Arduino or similar microcontroller.